1. Field of the Invention
The invention relates to a retarding device for an exerciser, more particularly to a retarding device which can replace conventional hydraulic cylinders used in exercisers.
2. Description of the Related Art
Conventional exercisers usually incorporate a hydraulic cylinder unit to serve as a retarding device therefor. Referring to FIGS. 1 and 2, a conventional hydraulic stepper is shown to comprise an L-shaped frame (1) and two pedal units (2) hinged respectively on two sides of the frame (1). A hydraulic cylinder (3, 4) is provided on top of each of the pedal units (2). Each of the hydraulic cylinders (3, 4) has one end hinged to the frame (1) and a piston shaft (3a, 4a) connected to the respective pedal unit (2). A fluid path (6) interconnects the hydraulic cylinders (3, 4). When pressure is applied so as to move a first one of the pedal units (2) downward, the first one of the pedal units (2) pivots about a pin (1a) on the frame (1), thereby pushing the piston shaft (3a) of the corresponding hydraulic cylinder (3) further into the cylinder body, as best illustrated in FIG. 2. Hydraulic oil (5) in the hydraulic cylinder (3) flows out of the latter and is transferred to the other hydraulic cylinder (4) via the fluid path (6). The piston shaft (4a) of the other hydraulic cylinder (4) is pushed downward, thereby causing a second one of the pedal units (2) to pivot upwardly. This illustrates how reciprocating movement of the pedal units (2) is achieved in the conventional hydraulic stepper.
The main drawbacks of using hydraulic cylinder units as the retarding device in an exerciser are as follows:
1. Leakage of hydraulic oil in the hydraulic cylinder units can easily occur, thus hindering the proper operation of the exerciser.
2. The hydraulic cylinder units are relatively expensive, thereby increasing the cost of the exerciser.